Annual decline of ventilatory capacity and change in acute respiratory response in hemp exposure over a 10-year period.

Abstract

A follow-up study of the effect of exposure to hemp dust on respiratory function over a 10-year period (1963–1973) was conducted in 24 female non-smoking hemp workers. The prevalence of byssinosis in 1973 (70.8%) was found to be significantly higher than 10 years earlier in 1963 (33%) (P<0.01). The prevalence of all other chronic respiratory symptoms was also considerably increased. In the control group the prevalence of all chronic respiratory symptoms was practically the same during both surveys. In hemp workers, there was a significant acute fall over the work shift in FEV1.0 (1-second forced expiratory volume) and FVC (forced vital capacity), both in 1963 and 1973 (P<0.01), except in the group of workers who did not have byssinosis either in 1963 or in 1973. The lowest mean annual decline of FEV1.0 within the 10-year period was found in the group without byssinosis in both 1963 and in 1973 (27 ml), followed by the group without byssinosis in 1963 but with byssinosis in 1973 (38 ml). The largest annual decline was observed in the subjects with byssinosis during both surveys (55 ml). The mean annual FEV1.0 decline in the control group was 22 ml.